Blow-out preventer



May 23, 1933. w. 1.. PEARCE BLOW-OUT PREVENTER 7 Filed Sept. 15, 1930Patented May 23, 1933 2 UNITED STATES WILLIAM L. PEARCE, OF HOUSTON,TEXAS BLOW-OUT IPREVENTER Application filed September 15, 1930. SerialNo. 481,990.

This invention relates to a blow out preventer.

One object of the invention is to provide apparatus for use inwelldrilling and the particular object is to provide a blow outpreventer whereby a fluid tight seal may be formed between the outerpipe or casing and an inner pipe, such as a drill stem therein, in awell bore.

Another object of the invention is to provide a blow out preventer ofthe character described embodying a suitable housing on the well casinghaving upwardly tapering Walls and confronting arouate packing orsealing members adapted to form a seal between said upwardly convergingwalls and the inner pipe, and means controllable by pressure fluid formoving said sealing members into active position to form said seal aboutthe inner pipe.

The invention further comprehends means for forming a permanent sealbetween the inner pipe and the well casing when the escape of pressurefluid in the Well has been placed under control by the blow outpreventer hereinabove referred to.

The apparatus referred to and hereinafter more specifically described isprimarily intended to prevent the escape of fluid under pressure whichis encountered in a well bore in carrying on drilling or producingoperations.

With the above and other objects in view the invention has particularrelation to cer tain novel features of construction, operation andarrangements of parts, an example of which is given in thisspecification and illustrated in the accompanying drawing, wherein:

Figure 1 shows the side elevation, partly in section, of the apparatusinstalled on a well casing, and

Figure 2 shows a cross sectional view, taken on the line 22 of Figure 1.

In the drawing the numeral 1 designates a well casing as set in a wellbore. Attached to the upper end of this casing by the coupling 2 thereis a housing, designatedgenerally by the numeral 3 and composed of theupper and lower sections 4, 5. The upper section 4 tapers upwardly, thatis, it is substantially conical in contour, and whose upper end has thecylindrical shaped inter nally threaded neck 6 with the internal annularflange 7 at the lower end of said neck,- said parts 4, 6 and 7 beingpreferably formed integrally together. The upper end of the lowersection 5 has an outwardly and upwardly flared portion 8 and the lowermargin of the upper section 4 and the outer margin of the outwardlyflared portion 8 are formed with coinciding annular flanges 9 and 10which fit together and are secured together by means of the marginalbolts 11.

There are-the confronting arcuate packing or sealing members 12, 12shaped to conform to the contour of and to fit closely around the innerpipe 13 and Whose outer sides conform in shape to the upwardly taperinginside wall of the housing section 79 4. There are the guide rods 1 1,14 whose upper ends are fitted into suitable bearings in the flange 7and Whose lower ends are threaded into the outwardly flared portion 8 ofthe housing, said guide rods being arranged parallel with the innerwalls of the section 4 and fitting through suitable bearings in thepacking members 12 and-011 which said members slide. These packingmembers 12 are preferably formed of tough rubber and their lower endsare'reinforced by suitable metal plates 15, 15. Anchored to theunderside of the outwardly turned portion 8 of the lower section 5 thereare the oppositely arranged fluid pressure cylinders 16,16. In apreferred form of the construction the upper ends of these cylinders maybe screwed into the heads 17, 17 which have the outwardly turned cars18, 18 to receive corresponding clamp bolts 11 and these heads may beadditionally secured in place by means of set bolts as 19 which areinserted through the outwardly turned portion 8 and screwed into saidrespective heads. In the cylinders are the pistons 20 which areconnected to the lower ends of the piston rods 21. These rods workthrough suitable stuffing boxes 22 and their upper ends work against,but are not necessarily connected to, the reinforcing plates 15. Thesepiston rods work substantially parallel to the corresponding guides 14.There is a fluid pressure inlet line 23 preferably a steam line leadingfrom a suitable source which has the branches 24, 24 controlled by aconventional three-way valve 25 which is located at a convenientdistance from the well so that it may be manipulated with safety in caseof a blow out. One of the branches 24 is connected into the deliveryline 26 which in turn is connected into the outer ends of the cylinders16. The other branch 24 is connected into a delivery line 27 which inturn is connected into the inner ends of said cylinders 16. When thevalve 25 is manipulated into one position it will permit the delivery offluid under pressure into the line 26 and thence into the outer ends ofthe cylinders 16 and the pistons will be thereby driven upwardly forcingthe sealing members 12 upwardly and inwardly, closely about the innerpipe to form a close seal to prevent the escape of internal pressurefrom the well around the inner pipe 18. When said sealing members 12 arein said seated position the inner pipe 13 may be lowered through theblow out preventer and the external couplings connecting sections ofsaid inner pipe may be passed through between said sealing members 12and a tight joint still maintained to prevent the escape of internalpressure. In order to permit a coupling to so pass through the sealingmembers the upper ends of said members are beveled inwardly as at 28 tofacilitate such passage. When the valve 25 is manipulated into anotherposition, the pressure fluid will be permitted to pass into the deliveryline 27 and thence into the inner ends of the cylinders and the pistons20 will be thereby forced outwardly thus permitting the release of thesealing members 12 from about the inner pipe. As the plungers 20 aremoved in either direction the pressure fluid ahead of them may berelieved through the relief outlet 29. The valve 25 may be manipulatedinto position to close the supply line 23 and thus shut ofi the supplyof steam to the cylinders.

When the blowout preventeris in closed position the internal pressure inthe well may be relieved through line 30 leading out from the casingbeneath the preventer and controlled by a suitable valve 31.

That portion of the mechanism hereinabove described may be used whiledrilling operations are being carried on and while said operations arebeing carried on the sealing memliiers 12 will be in their downward andoutward position to not interfere with drilling operations but in case ablow out is threatened the valve 25 may be manipulated to admit steaminto the outer ends of the cylinders 16 so as to close the passagewayabout the inner pipe and prevent such blow out.

Within the neck 6 and seated on the flange 7 there is a metal ring 32Whose inner side is upwardly flared forming the seat 33 and closelysurrounding the inner pipe there is an annular sealing member 34preferably formed of resilient material such as rubber whose inner sidefits closely around said pipe and Whose outer side is tapered to conformto the contour of and to fit closely against the seat 33. When apermanent seal is desired about the inner pipe 13, as when the well hasbeen completed and the screen and packer are set a gland as 35 may bethreaded down into the neck 6 against the packing ring 84 so as tocompress the same inwardly against the inner pipe and outwardly againstthe inner wall of the neck 6 so as to form a permanent seal about saidinner pipe. The gland 35 is preferably formed of two vertical sections,each section having dowel pins 36 on one side and sockets as 37 on theother side, the dowels of one section fitting into the sockets of theother section to hold these gland sections in alignment so that thegland may be screwed into the neck 6. The upper end of the gland isenlarged as at 38 and has the upwardly flared seat 39 to receivesuitable pipe engaging slips as 40 which may be inserted around, andwhich will engage with, the inner pipe to hold it at any desired place.Surrounding the upper end of the gland 35 there is a band 41 provided topre vent the gland sections from spreading.

When the permanent seal has been set as above explained the sealingmembers 12 will then serve no further function and the steam may berelieved from the cylinders 15 and said sealing members permitted tomove into neutral or inactive position.

The drawing and description disclose What is now considered to be apreferred form of the invention by way of illustration only while thebroad principle of the invention will be defined by the appended claims.

What I claim is 2- 1. A blow out preventer for forming a seal between anouter casing and an inner pipe in a well bore and comprising a housingon the casing and having an upwardly tapering inside seat around theinner pipe, guides extending from th lower to the upper end of thehousing substantially parallel with said seat, confronting sealingmembers in the housing movable on said guides into active position toclose the passageway between said casing and inner pipe and intoinactive posit-ion to open said passageway, said sealing members beingformed of resilient material throughout and being shaped to fit aroundthe inner pipe and against said seat to form a fluid tight oint when insaid active position, rigid plates forming seats for said sealingmembers, means associated with the housing and operable by fluid underpressure against said plates and effective to move said sealing meansinto said active position and to amaze release the same to permit saidsealin means to move into said inactive position an means forcontrolling the application of pressure fluid to said moving means.

2. A blow out preventer for forming a seal between an outer casing andan inner p1pe in a well bore and comprising a housmg on the casinghaving a tapering seat around a the inner pipe and having inwardlyextended rod anchors above and beneath said seat, confronting sealingmembers in the housing movable into active position about the inner pipeand into inactive position away from said inner pipe,saidsealingmembersbeing formed of packing material and having reinforcing end plates andbeing shaped to fit closely between said seat and pipe, when in saidactive position, to completely close the passageway between the casingand inner pipe, rods on which the sealing members slide, said rodshaving their upper and lower ends anchored to said upper and loweranchors.

3. A blowout preventer for forming a seal between an outer casing and aninner pipe in a well bore and comprising a housing formed with upper andlower sections, said upper section tapering upwardly forming an insideupwardly tapering seat having an internal projection at the upper endthereof forming an anchor, the upper end of the lower section having anoutwardly and upwardly flared portion, said upper and lower sectionshaving coinciding annular flanges, cylinders on the outwardly turnedportion of said lower section having heads provided with outwardlyturned ears, bolts through said ears and said coinciding flanges wherebysaid upper and lower sections and said cylinders are secured together,confronting sealing members in the housing movable into active positionto close the passageway between the housing and an inner pipe thereinand movable into inactive position to open said passageway, said sealingmembers bein shaped to fit around the inner pipe and against said seatto form a fluid tight joint when in active position, pistons in saidcylinders, piston rods 01 the pistons operatrve against said sealingmembers, means for introducing fluid pressure in to and relieving thesame from said cylinders on either side of said pistons, rods secured tosaid anchor and to said outwardly turned portion on which said sealingmembers slide.

In testimony whereof I have sied my name to this specification.

WILLIAM L. PEARCE.

